To enact a policy, a leader needs votes from committee members with heterogeneous opposition intensities. She sequentially offers transfers in exchange for votes. The transfers are either promises paid only if the policy is put to a vote or paid up front. With transfer promises, the leader buys...

To enact a policy, a leader needs votes from committee members with heterogeneous opposition intensities. She sequentially offers transfers in exchange for votes. The transfers are either promises paid only if the policy passes or paid up front. With transfer promises, a vote costs nearly zero....